1. Field of the Invention
This invention relates to telescoping tubes used as support structures, especially as used in a support arm or standard for portable equipment such as cameras, musical cymbals, drums, and the like.
2. Description of Prior Art
Various support devices are utilized to support portable equipment such as musical drums or cymbals, microphones, speaker enclosures, stage lighting, cameras, and the like. Such support devices usually have an extentable standard or arm constructed as a plurality of interrelated structural members, with means for attaching the equipment to the structural members, and means for positioning and clamping the structural members in positions relative to one another. Generally, the structural members are nested hollow tubes, and two or more tubes are designed to collapse into one another for ease of storage or transport. Some type of metal fitting or clamp is usually attached to one end of a structural member to attach the supported equipment. The opposite end of the structural member is attached to other structural members in the support system by means of additional fittings of clamps. The fittings or clamps in combination with the interrelated structural members allow the musical instrument or equipment to be located in the desired vertical, horizontal, and angular position for use. The support systems are generally disassembled for transport or storage and reassembled for setup and reuse.
In conventional support systems, the relationship of the telescoping members is not maintained when disassembled, and the supported instrument or equipment must be repositioned each time in a tedious trial and error process.
One solution is the use of so-called xe2x80x9cmemory locksxe2x80x9d. U.S. Pat. No. 5,566,911 illustrates a typical example [see FIG. 5, #25]. The memory lock is a sleeve or collar fixed on a support tube in a desired location by means of a clamping screw. When the tube with memory lock is inserted into the top of a second, larger diameter tube, the memory lock hits the upper surface of the second tube and prevents further insertion. This provides a repeatable extension position for reassembly of the support tubes. However, a major drawback is that the support tubes with memory locks cannot be collapsed into one another for storage or transport, but must be disassembled into numerous individual tubes. The individual tubes are cumbersome to store or carry, take up more space than telescoping tubes, and expose the full tube surface to damage from other equipment during transport. Typically, several different independent support structures or stands are used in a single setup to support various pieces of equipment. This further complicates re-assembly, since the correct tubes must be re-matched to the appropriate support stand for correct re-assembly.
Another solution is described in U.S. Pat. No. 4,185,808. See especially FIGS. 3 and 4, where a first connector part 36 is clamped onto the inner tube. The first connector part 36 has a key 50 that slides into a slot 70 on a second connector part 38 on the outer tube. This indexes the tubes at a repeatable rotational position in addition to a repeatable extension position. However, as with U.S. Pat. No. 5,566,911 above, the inner tube cannot be retracted into the outer tube, so the disadvantages mentioned above apply.
Another solution is described in U.S. Pat. No. 4,606,525. In this invention, an adjustable flexible strand is fixed lengthwise to the inside of the various tubular sections. When the sections are fully extended, the strand is pulled tight, blocking further extension and thus providing an extension reference. The sections can be telescoped into one another since the strand is inside of the tubing and is flexible. A disadvantage of this solution is the lack of positive rotational positioning. The extended strand provides a height reference, but does not address the rotational position of one tube relative to the other, thus not fully addressing the desire for repeatable positioning.
Thus, there is a need for an improved method for repeatable positioning of equipment supports, such as musical instrument supports, that overcomes the current limitations of the art, examples of which include:
U.S. Pat. No. 6,162,978 xe2x80x9cAdjusting Structure for Musical Instrument Supportersxe2x80x9d
U.S. Pat. No. 6,075,190 xe2x80x9cDrum Holderxe2x80x9d
U.S. Pat. No. 5,566,911 xe2x80x9cStand for Drum and Cymbalxe2x80x9d
U.S. Pat. No. 4,606,525 xe2x80x9cHeight Adjustment of Music Standxe2x80x9d
U.S. Pat. No. 4,185,808 xe2x80x9cConnector Hardware for Percussive Instrumentsxe2x80x9d
A general object of this invention to provide a means for repeatably positioning telescoping standards on equipment support stands for ease of setup and use.
One object is to provide means for locating nested tubular members in specific extension positions relative to one another that incorporates the ability to easily return to the same relative extension positions after disassembly and reassembly.
A second object is to provide means for locating nested tubular members in specific rotational positions relative to one another that incorporates the ability to easily return to the same relative rotational positions after disassembly and reassembly.
A third object is to provide such repeatable positioning means while retaining the ability to telescope one tubular member into another for storage or transport without removing the repositioning device.
A fourth object is to provide means to easily set a desired repeatable extension and rotational position with minimal trial and error.
A fifth object is to integrate a repeatable positioning system internally to telescoping tube clamps for a satisfactory appearance and ease of use.
These objectives are met in an adjustable stop attached to the smaller of two nested telescoping tubes. The stop is axially and rotationally adjustable on the smaller tube. The stop is smaller in diameter than the inner diameter of the larger tube. The stop has a detent for a pin extending inward from a tube clamp on the larger tube. The detent receives and releases the pin in both axial directions. This provides a stop for both the relative extension and rotational positions of the tubes, and also allows the smaller tube to retract into the larger tube. The tube clamp is used to fix the tubes at the detent position. The tube clamp is used conventionally to initially establish or readjust a desired detent position.